In rotating machines such as a turbine and a compressor, a rotor usually rotates at a high speed in an operating state. Therefore, when an abnormality such as damage occurs in the rotor, for example, the abnormality such as damage increases as detection of the abnormality is delayed, so that the rotating machine may stop due to the abnormality. Accordingly, such an abnormality in a rotating machine is desired to be detected and notified promptly.
For example, an abnormal sliding diagnostic device disclosed in Patent Literature 1 uses an AE (Acoustic Emission) sensor to detect an AE signal from a rotating machine and performs frequency analysis on the detected AE signal to thereby determine the presence/absence and, if any, the position and the degree of an abnormal sliding and display a determination result.
If the chronological change in the operating state of a rotating machine can be recognized, an operator can find a chronological change in the operating state of the rotating machine, which makes it possible to detect an abnormality in the rotating machine more promptly. However, in the conventional technique disclosed in Patent Literature 1, although a determination result about the presence/absence, the position, and the degree of an abnormal sliding is displayed, the chronological change in determination results is not displayed. Therefore, although the conventional technique allows recognition of the presence/absence and the like of an abnormality in a rotating machine, it has been difficult to promptly detect the abnormality.